Exosome sourcing has matured faster than the vocabulary used to sell it. Two suppliers can describe nearly identical products in nearly identical language, and the difference only shows when you ask for documentation. A structured set of questions, asked before the first order, is the most reliable way to tell a manufacturer from a reseller, and a controlled process from a confident brochure.
The checklist below follows the order most provider diligence takes: the identity of the material first, then process, testing, paperwork, logistics, and finally the supplier’s own conduct.
7 Questions to Ask Before Choosing an Exosome Supplier
1. What exactly is the material, and where does it come from?
Start with category. “Exosome” is often used loosely for products that differ in source, composition, and handling. Ask which cell type and tissue the vesicles are derived from, how donor material is screened, and whether the product is a purified extracellular vesicle preparation or a conditioned medium. These are not interchangeable. A supplier who cannot state the difference plainly deserves closer scrutiny.
It also helps to confirm that the supplier understands where exosome-based materials sit relative to cell-based ones. That boundary carries both scientific and regulatory weight, which we examine in exosomes vs. stem cells: why the distinction is both clinical and legal. For a side-by-side view of composition and handling, see this comparison of exosomes, stem cells, and PRP.
2. How is it manufactured, and under what controls?
Ask whether production takes place under cGMP, and in what class of cleanroom. ISO 7 (ISO 14644-1 Class 7) is a common benchmark for controlled manufacturing environments. Ask for the certificate, not the claim.
Then ask about isolation. Tangential flow filtration, size-exclusion chromatography, ultracentrifugation, or a combination can all be legitimate. What matters is whether the method is validated and reproducible. A supplier with a stable process can tell you how lot-to-lot variation is monitored and what happens when a lot falls outside specification.
3. What is tested on every batch?
The operative word is every. A credible supplier can describe a standing panel applied to each lot:
- Identity: confirmation that the material is what the label says, characterized in line with the reporting framework published by the International Society for Extracellular Vesicles (MISEV).
- Particle characterization: size distribution and concentration, by a named method.
- Sterility: documented per lot.
- Mycoplasma: documented per lot.
- Potency: with a clear explanation of how potency is defined for this product, since approaches vary across manufacturers.
Characterization performed once during development and assumed thereafter is not batch testing. Ask whether results are generated per lot and whether testing is in-house, independent, or both.
4. Can I see a Certificate of Analysis for my lot?
A Certificate of Analysis should be tied to a batch number, not a product name. It should list each test, the method used, the specification, the result, and the date, and it should be issued by an identifiable quality function.
Be cautious if results are identical across different lots, if methods are missing, or if the document reads like a generic template. Ask two things: can you review a representative COA before ordering, and how will you retrieve the COA for your specific batch after delivery? A supplier whose COAs are organized and retrievable by batch usually has the quality system behind them.
5. How is the product stored, shipped, and traced?
Biological material is only as good as its handling. Ask for the storage format (lyophilized or frozen), temperature requirements, and shelf life by lot. Ask how shipments are validated and what the protocol is if there is a transit excursion. Finally, ask whether each lot can be traced from raw material through to your delivery. Traceability is also what makes a recall, or a simple clarification, possible.
6. How does the supplier handle verification?
A serious supplier knows who it is selling to. Provider verification before pricing and ordering unlock is a mark of a controlled channel. A supplier that quotes freely to anyone is probably moving inventory rather than managing a quality relationship.
Ask which jurisdictions the supplier serves and under what local licenses. Clear answers here tend to correlate with clear answers everywhere else.
7. How does the supplier talk about the product?
Listen closely to the language. Exosome materials supplied for research should be described as research materials. A supplier that attributes therapeutic outcomes to a research product, or promises clinical results, is signaling that its marketing has outpaced its compliance.
Ask how the supplier describes regulatory status in your market. A knowledgeable supplier will refer to appropriate regulatory frameworks, including IND pathways where applicable, and will not deflect the question.
Putting the checklist to work
The most practical way to use these questions is as a one-page scorecard. Run every shortlisted supplier through the same seven sections, record the answers in writing, and compare. Suppliers who welcome the exercise are, in our experience, the ones with answers to give. Suppliers who treat it as an imposition have told you something as well.
At CellGenic, batch-level testing (identity, sterility, mycoplasma, and potency), lot-specific COAs, cGMP manufacturing, and verified-provider access are the baseline, not an add-on. To see how this applies in practice, explore the CellGenic exosome range or begin provider verification at CellGenic.
All products are supplied for laboratory research use only and are intended for handling by licensed, qualified professionals.
